Solve for $z$, $ \dfrac{2}{z + 3} = \dfrac{1}{5} $
Multiply both sides of the equation by $z + 3$ $ 2 = \dfrac{z + 3}{5} $ Multiply both sides of the equation by $5$ $ 10 = z + 3 $ $10 = z + 3$ $7 = z$ $z = 7$ $z = \dfrac{7}{1}$